db.PICompanyAssessmentShortReport.find({ "LevelOfInvolvement": { $exists: 0 }})

db.PICompanyAssessment.aggregate([
    { $unwind: "$Indicators"},
    { $project: { _id: 0, "CompanyId": "$_id", "CategorySymbol": "$Indicators.CategorySymbol", "LevelOfInvolvement": "$Indicators.LevelOfInvolvement" }}
]).forEach(function(item){
   db.PICompanyAssessmentShortReport.update({CompanyId: item.CompanyId, CategorySymbol: item.CategorySymbol }, { $set: { "LevelOfInvolvement": item.LevelOfInvolvement }}, { multi: true })    
})
    
